The present invention relates to the field of measuring technique, using a computer to obtain and process metrological information of general and specific applications.
Methods of measuring using a computer are known, which are based on a conversion of a physical value into an electrical voltage, containing a metrological information in its level (Japanese application 5-25409, GO1D 9/00 04/09/93 and International application 94/12940, GO6F 15/20, 06/09/94). A method of conversion of a physical value into an electrical voltage of its level is known, in which the information about the value to be measured is contained in a length of pulse (period) of voltage. (xe2x80x9cConnection of sensors and data input devices with a computer IBM PC, edited by U. Tompkins and J. Webster, M. xe2x80x9cMIRxe2x80x9d 1999, page 312). The methods are realized by corresponding devices.
On the other hand, in metrology and automation a great class of sensors is known (a sensor is a sensitive element which generates an electrical voltage directly or jointly with a current source) which initially form an output signal as an alternating voltage which contains the information in an amplitude and/or in a frequency (period).
At the same time many sensors of direct voltage are often characterized by an intermediate conversion of the direct voltage into alternating voltage due to the complications of drifts, noises of direct current amplifiers, interferences, instability of a power source, transmission of direct current signals, and because of this the necessity of decoupling of the object of measurement with the measuring devices. In principle contactless measurements are performed as to the alternating signal. Therefore the output signal of the sensor is preferably to be formed in the form of alternating voltage or current.
From the metrological point of view during this process for the accuracy, a range which covers four decimals orders of frequency measurement is sufficient.
A method is also known for measuring a physical value (application of France 2697080, GO1B 3/02 04/22194) in accordance with which an a periodical signal is formed with a length proportional to the value to be measured. For this purpose the standard capacitor is charged through a resistor, with an electrical resistance sensitive to the value to be measured.
The device which realizes this method includes a thermal resistor and several elements which are connected with it in series: a capacitor and a transistor, with the transistor connected parallel to the capacitor. These elements and the thermal resistor form an oscillating circuit, and parameters of the elements provide a length of the output signal. The above listed elements and a Schmidt trigger form a formatter of pulse electric voltage. The output of the formatter is connected with a digital input of the computer. The device operates in the following manner. In response to a computer signal, the transistor is closed and at the same moment an inner time counter is started in the computer. The capacitor through the thermal resistor is charged with electric current to the moment of switching of the Schmidt trigger. This moment of charging of the capacitor is fixed in that, the signal of voltage change from the output of the Schmidt trigger is supplied into the computer so as to stop its internal counter, and based on the signal the computer converts the transistor into the saturation mode. The capacitor discharge is performed through the inner resistance of the transistor. Information about the value to be measured is contained in the internal counter of the computer.
This method and device allow to measure a physical value (temperature). Substantial disadvantages of the known method and the device which realizes it are the following:
low accuracy of measurement due to generation of systematic mistakes of measurements because of non linearty and temperature dependence of parameters of formatter components;
limited functional possibility, which do not allow using of widely used personal computers without special additional devices and program-drivers.
A main object of the invention is to increase accuracy and stability of measurement with simultaneous expansion of functional possibilities, simplification and unification of a procedure, the treatment and program and supply of input/output, accumulation, processing, registration and visualization of measuring information, which allows the expansion of areas of measurements of physical parameters, including their availability for (mass) consumer.
Additional objections are:
increase of reliability measurements;
providing of electrical decoupling, up to remote cordless communication between components of a measuring system;
increase of resolution ability of measurements.
The main objective of measuring a physical value with the use of a computer is resolved in that, the sensitive element is subjected to a physical action, and electro-oscillating process is organized using an electrical parameter of the sensing element, under the action of the electro-oscillating process an electrical voltage is formed which is supplied to an input of computers, and in accordance with the present invention the electro-oscillating process is organized to be a periodical process, a voltage is formed with a level and frequency of information-meaningful components of its frequency spectrum which satisfy, within a range of measurement of a physical value, the parameters of input of an audio adapter of the computer, which corresponds to the specification of Multimedia Personal Computer (MPC), and during this process the input of the computer is the input of its audio adapter.
Thereby, in accordance with the proposed method, an action is applied to the sensitive element whose electrical parameter depends on the physical value characterizing the given physical action, the electrical signal is formed whose parameters changes in accordance with the change of the parameter of the sensitive element, and the electrical signal is supplied into the computer for its processing, and at the same time the computer is used which is provided with an audio adapter, and the said cylindrical signal is formed as a periodical signal whose amplitude and frequency correspond to the parameters of the input of the computer audio adapter, to which the formed signal is supplied.
The objective is also resolved by a device which includes a computer, a sensing element, a formatter of an alternating electrical voltage connected with it and connecting a frequency-providing element, wherein in accordance with the invention, the formatter additionally contains a converter of voltage level whose output is an output of the formatter, the output of the formatter is connected with the input of the computer audio adapter which corresponds to the specification Multimedia Personal Computer, frequency-providing elements of the formatter have parameters which provide a frequency of information-valuable components of a frequency spectrum of the output voltage within limits which satisfy the parameters of the input of the computer audio adapter in the whole range of the measurement of the physical value.
The device in accordance with the present invention provides input/output, accumulation and registration of the metrological information.
Therefore, the essence of the proposed method and device is embodied in the following:
1. Formation of a sensor signal in form of a periodical (alternating) voltage;
2. Supply of the signal to an input of the computer audio adapter;
3. Use of the computer which includes the audio adapter representing a unified assembly with respect to the system program set.
Therefore, with an insignificant modification, and many cases a simplification of a procedure and a diagram of forming of the output sensor signal and its supply to the input of the computer audio adapter, it is no longer necessary to develop programs-drivers of input/output of the information by a user.
Because of this, the accuracy of measurements is increased and a unification of the program for input/output of the information is provided, which is accepted by various sensors of one or several uniform or different physical values.
In accordance with a preferable embodiment of the device of the present invention, the converter of the voltage level is formed either as mutually coordinated opto-electronic transmitter and the receiver connected with the input of the audio adapter, or a transformer with a secondary winding connected with the input of the audio adapter.
The best results are obtained in this device in accordance with this invention, in which for measuring of two different physical values, the formatters are connected with two (left and right) channels of the input of the audio adapter.
The additional objectives are resolved also in that, in accordance with the invention, the device includes an identifier of the sensitive element and the formatter, connected with a digital input of the computer, and also in that it is provided with a block of controlling the formatter, with the input of the block connected to the digital output of the computer (for example, series or parallel interface) or digital output of the computer audio adapter, (for example MIDI-interface) and the output of the block is connected with the formatter.